That appears to be the call to "CreatePipe", I would guess, but I've no idea why that would get stuck. Is it a specific problem with a new version of your application? Did it not occur with older versions of your application? Or did this problem show up for the user at some point (without knowing why) and now it occurs with every version of your application (that has madExcept built in)?

A wild guess could be an anti-malware software thinking that your application (or madExcept) is doing something dangerous. But a freeze in "CreatePipe"? I've never seen this problem reported before!

One thing you could try is to send the customer an "empty" exe file compiled with madExcept, to see if that freeze, too?